Respiratory Noises in Infants and Children: How Useful are They Clinically?
Dagne Assefa, MD Pediatric Lung Center Bon Secours Conflict of Interest: None
Objectives:
Review the differential diagnosis of noisy breathing in infants and young children.
Review the indication for more invasive studies (e.g. bronchoscopy) in infants with respiratory noises.
Review the importance of the correct diagnosis for a wheezy infant and preschool child. Differentiate from imitators.
Review management of wheezing infants and preschool children.
How common is ‘‘noisy breathing’’ in Infants and Young Children
‘‘noisy breathing’’ is extremely common in infants and young children. Noisy breathing means airway obstruction
The most frequently used terms are ‘‘wheeze,’’ ‘‘rattle,’’ ‘‘stridor,’’ ‘‘snore,’’ and ‘‘nasal snuffle/snort.’’
Conventional wisdom, based on empiric evidence and basic physiology, is that these noises emanate from specific anatomic sites within the respiratory system.
Thus, correctly identifying these noises is of major clinical relevance, in terms of localizing both the site of obstruction, and the most likely underlying cause How common is ‘‘noisy breathing’’ in Infants and Young Children Respiratory noises emanate from specific anatomic sites within the respiratory system. There only are 4 possibilities if one groups them : 1. Nose and Nasopharynx 2. Larynx (and throat) 3. Trachea and Major bronchi 4. Peripheral airways
#1 and #2 are EXTRATHORACIC (above the thoracic inlet) and are characterized by predominantly INSPIRATORY obstruction and noise.
#3 and #4 are INTRATHORACIC and are characterized by predominantly EXPIRATORY obstruction and noise
So the ESSENTIAL QUESTION to answer is this: is the obstruction and noise predominantly INSPIRATORY or EXPIRATORY? Common noises and the site of origin Noise Phase of Site of Origin Resp Rattle Insp/exp intra- and/or extrathoracic airways Stridor Pred Insp Extrathoracic Airways Wheeze Pred Exp Intrathoracic airway Snore Pred Insp Oro-naso-pharyngeal airway Snuffle/ Pred Insp Nasal passages/Nasopharynx snort Grunt Expiratory Alveoli/lung parenchyma CASE 1
A 10-month-old male “noisy breathing” for 6 weeks
A varying prominent “noisy” breathing throughout the day. + wet cough. The noise clears after coughing Symptoms varies throughout the day Had bronchiolitis 10 weeks ago. History of eczema Rattle (aka upper airway sound, transmitted sounds, or coarse ronchi)
The result of excessive secretions in the large airways, which are presumably moving with normal respiration. May be inspiratory or expiratory. Commonly mislabeled as a ‘‘wheeze,’’ Common in the first year of life but rarely heard after 15-18 months of life. Causes: acute viral bronchitis/bronchiolitis (infants) Inability to cough and/or swallow normal secretions (In neurologic or neuromuscular condition) Specific intervention are rarely indicated Persistent bacterial bronchitis
Increasingly recognized as a cause of chronic wet cough, particularly in young children (<5 years of age).
PBB – diagnostic criteria isolated chronic wet-moist cough + Rattle resolution of the cough with antibiotic treatment absence of an alternative cause of the cough
Differential diagnosis of PBB
Asthma: PBB does not usually respond to bronchodilators
Auscultation typically reveals a rattling sound reflective of airway secretions (expiratory rhonchi) rather than true wheezing.
Asthma and PBB can coexist.
Foreign body aspiration: If cough began suddenly after choking, or while eating or playing in a young child → evaluate for the possibility of a foreign body.
Treatment of PBB
Usually require a prolonged course of antibiotics, generally two to four weeks
Shorter courses frequently lead to relapse.
The antibiotics: Empiric vs. culture based
Appropriate antibiotic therapy: Amoxicillin-Clavulanate Third generation cephalosporins to cover beta-lactamase producing organisms and S. pneumoniae in the community. What caused the Problem?
A 9-week-old female “noisy breathing”
A varying prominent “noisy” breathing sound especially during agitation
Symptoms varies depending on body position.
Onset of symptoms after 3 weeks of life Stridor
Indicates obstruction to airflow in the extrathoracic airways down to the level of the thoracic inlet.
Predominantly inspiratory, but can occur in both phases of respiration (severe obstruction).
Laryngomalacia is by far the most common cause.
Louder with crying, feeding, and supine but softer when quietly sleeping and prone.
Often associated with other noises such as ‘‘stertor’’ (or ‘‘clucking’’ noise), but a normal cry (voice), and normal cough. Laryngomalacia
A result of collapse of the supraglottic structure during inspiration. Assessing stridor
In infants with persistent stridor, but no significant increase in the work of breathing, no cough, normal cry, no apnea or cyanotic episodes, and thriving, then laryngomalacia is the most likely cause. No further investigation is warranted apart from follow-up review. Quality of evidence: High. Large observational studies with consistent findings.
If stridor is persistent and associated with any of the above features, then consider significant upper airway pathology Investigation: bronchoscopy. Quality of evidence: Moderate. Mostly from small cohorts and case series. What caused the Problem?
History • A 5 month-old boy awakens at midnight with noisy breathing . He had been well until 2 days ago when he developed rhinorrhea and cough. • Parents report hoarse voice Physical • Physical examination reveals a temperature of 38.3°C What caused the Problem? Croup (laryngotracheitis)
It is a clinical syndrome characterized by inspiratory stridor, harsh barking cough, and hoarseness. Age: 6 months to 3 years of age. M>F.
The most common viral causes are: parainfluenza 1 & 3 and RSV. Other rare: rhinovirus, adenovirus, measles virus, and m. pneumoniae. It is the most common cause of infectious acute upper airway obstruction. Season: parainfluenza in the fall; RSV in winter Assessing Acute stridor
If stridor is acute, and associated with symptoms and signs of a viral respiratory tract infection plus a brassy (croupy) cough, then viral croup (laryngotracheobronchitis) is most likely.
If the acute stridor occurs in the absence of a viral respiratory tract infection, then the possibility of a large ingested foreign body should be considered, particularly if there is any difficulty in swallowing. Quality of evidence: Moderate. Small cohorts and case series. CROUP: DIFFERENTIAL DIAGNOSIS
The age of the child The younger the age → structural airway problems.
The character of the stridor Inspiratory/expiratory stridor → fixed tracheal obstruction (suglottic stenosis, retropharyngeal abscess).
The level of toxicity of the child Croup → nontoxic. Bacterial tracheitis, epiglottitis or viral supraglottitis → Toxic.
CROUP ASSESSMENT OF SEVERITY
General appearance: agitated? tiring from the effort of breathing? decreasing level of consciousness?
Degree of respiratory distress: stridor at rest? tracheal tug or chest wall retractions? changing RR or HR ?Assessment of breathing in children
Cyanosis or extreme pallor?
Oxygen desaturation as indicated by oximetry is a late sign and unreliable for croup severity. Oximetry reading is never a surrogate for clinical examination. Assessment of breathing in children
Signs of increased effort (work) of breathing Increased respiratory frequency Chest indrawing (recession) Accessory muscle use Alae nasi flaring Tracheal tug Stridor Wheezing Grunting or gasping Signs of decreased efficacy Decreased chest expansion Decreased, absent or asymmetrical breath sounds
Reduction in SaO2 on room air ASSESSING CROUP SEVERITY
Oximetry : routinely used in the ER. • Oximetry not a substitution for a good clinical assessment. • Oxygen saturation not always accurate in predicting severity of croup. Clinical scoring systems (such as Westley croup score) • Important in research studies, but limited value in clinical practice. Lateral airways radiograph: • Mostly not necessary ( croup is a clinical diagnosis and no additional information in the management of croup can be gained from the X-ray) Chest radiograph:
• Not indicated routinely. • Unless uncertainty about the diagnosis.
Treatment of Croup
Depend upon the severity of symptoms and the presence of risk factors for rapid progression.
There is no definitive treatment for the viruses that cause croup.
Pharmacologic therapy is directed toward decreasing airway edema and supportive care is directed toward the provision of respiratory support and the maintenance of hydration. CROUP: Treatment
Supportive care Pharmacological
Corticosteroids Administration of If the stridor is present at rest (obstruction likely moderately humidified air/O2 severe) Steroids indicated Systemic vs. inhaled steroids Provision of Quality of evidence: High. intravenous fluids Systematic reviews. Nebulized adrenaline Monitoring for Racemic and L-adrenaline worsening respiratory distress. Heli-Ox
What caused the Problem? Treatment of airway hemangiomas
Propranolol with or without systemic glucocorticoids is generally the first line of therapy for children with enlarging airway hemangiomas.
Laser ablation is an occasional second-line therapy.
Tracheotomy may also be required. What caused the Problem?
14 mo. old boy with cough and rhinitis for four days.
+ respiratory noises, worsening over the last 2 days
Decreased appetite the last 24 hrs.
Both parents smoke. A Wheeze
Continuous musical sound – can be high-pitched or low-pitched.
Can consist single (Monophonic) or multiple notes (Polyphonic)
Can occur during inspiration or expiration. Often associated with prolonged expiration
Wheeze emanates from the intrathoracic airways: The large, central airways The small, peripheral airways.
Intensity of the wheeze is a poor indicator of the severity of the obstruction. If the obstruction is extremely severe the wheeze may become inaudible. Wheeze as a result of large airways obstruction
When a structural lesion obstructs airflow in the large airways, the wheeze is localized on auscultation, and is classically termed ‘‘monophonic.’’ Causes: Intrinsic: Inhaled foreign body, endobronchial tuberculosis, and bronchial adenoma.
Extrinsic compression: enlarged mediastinal lymph nodes, benign or malignant mediastinal tumors, and achalasia
Wheeze as a result of small airways obstruction
In the presence of extensive small airway narrowing, the resultant high pleural pressure swings can cause compression (inward collapse) of the large airways during expiration, producing generalized expiratory wheezing
The very young are particularly prone to this because their large airways are relatively soft (‘‘floppy’’) and more prone to collapse.
Because the specific site of the large airway obstruction noise is variable, the noise is termed ‘‘polyphonic.’’
Common Causes: acute viral bronchiolitis, asthma, various forms of tracheomalacia and/or bronchomalacia, How common is wheezing in Infants?
Very uncommon clinical finding during the 1st 1-2 month of life.
Occurs in more than 30% of young children during the first 3 years of life.
The prevalence falls to about 15% in older children. Wheezes and other noises… Fall into one of the two categories...
Structural abnormalities Functional abnormalities Tracheo-bronchomalacia Asthma Vascular compression/ rings Gastroesophageal reflux Tracheal stenosis/webs Recurrent aspiration Cystic lesions/masses Cystic fibrosis Tumors/lymphadenopathy Immunodeficiency Cardiomegaly Primary ciliary dyskinesia Retrognathia (Pierre-Robin Bronchopulmonary dysplasia syndrome) Retained foreign body Adenotonsillar hypertrophy Bronchiolitis obliterans Pulmonary edema Vocal cord dysfunction The Dilemma
Diagnosing asthma in young children is ….. Important! Most severe asthma starts in early life Early treatment may improve outcome Early diagnosis avoids lots of misery/admissions/consultations
Diagnosing asthma in young children is …. difficult ! A range of disorders which overlap Objective testing difficult Problems with Asthma Symptoms
Dependent on parental reporting
Confusion of respiratory sounds Night time symptoms difficult to quantify
Recollection of symptoms changes When a "wheeze" is not a wheeze!
298 infants <6 months of age 30% of parents reported wheezing in the previous 24 h 11% of the infants said to have had noisy breathing from birth . Closer questioning, the investigators determined that stridor accounted for 1% of the total upper airways noises 93% classical wheeze only 2%. Conclusion: The vast majority of infants, therefore, had snuffly or upper airway noises; many of the latter are likely to have rattles.
Thornton AJ, Morley CJ, Hewson PH, Cole TJ, Fowler MA, Tunnacliffe JM.. Arch Dis Child 1990; 65: 280±285. Wheeze, perception and interpretation: what do we hear? • Parents differ widely in understanding and definition of wheeze (whistling, squeaking, rattling, gasping)
• If based on parental report alone, children may be labelled as having wheeze when they don't
CONCLUSION: ENSURE that wheeze has been observed by you/colleague: Ask for additional visits during wheezy episodes!
Elphick HE. Arch Dis Child 2001; 84:35-9. Asthma phenotypes
Childhood asthma childhood onset asthma
adult onset preschool “wheeze” asthma
childhood adulthood
age Characteristics of Preschool Children with Wheeze
Frequency of episodes Most children wheeze Occasionally, some have frequent episodes
Severity of episodes Ranging from very mild to severe and life-threatening
Temporal pattern Only wheezing with viral colds or in response to other triggers
Long-term outcome of Transient versus persistent symptoms wheeze Phenotype classifications to understand mechanisms / outcome: Duration of wheeze
Stein RT et al Thorax 1997 Definition
Transient •Symptoms (at least one episode of viral wheeze) before 3 yrs •No symptoms after 6 yrs
Persistent •Symptoms before 3 yrs IgE- •Continue > 6 years associated
Late-onset •Symptoms after 3 years (no viral st Non-atopic wheeze during the 1 3 years of life and have wheeze at 6 years of age)
Lung function at infancy and 6 years of age Retrospective assignment of phenotype expressed in Z-scores by wheezing group
J Allergy Clin Immunol 2003;111:661-75.) Clinical phenotype classification for management of preschool wheeze
Temporal pattern of Definition wheeze Episodic (viral) •Wheeze at discrete times wheeze •Often with evidence of viral cold •NO symptoms in between episodes Multiple-trigger •Wheeze with discrete wheeze exacerbations •AND symptoms between episodes
Prospective assignment of phenotype Brand P et al ERJ 2008;32:1096-110 Clinical preschool wheeze phenotypes seem pathologically distinct
Episodic (viral) wheeze Multi-trigger wheeze
No increase in Increased inflammation inflammation BAL: neutrophilic /eosinophilic Biopsy: eosinophilic No elevation of exhaled nitric oxide Elevated exhaled nitric oxide No remodelling Airway remodelling present Pathologically resemble non-wheezing controls Pathologically resemble “asthma” Natural History of Childhood Asthma: Well Established by Multiple Studies
Horak E, Lanigan A, Roberts M et al. 2003; BMJ 326: 422-423. Mimics of asthma • Mucociliary dysfunction (PCD, CF)
• Esophageal diseases (GER/Aspiration)
• Congenital anomalies (Cardiac/pulmonary)
• Immunodeficiency
• Bronchiolitis obliterans
Mimics of Asthma: Mucociliary Dysfunction
Cystic Fibrosis Primary Ciliary Dyskenesia 46 CLUES TO CF: Clubbing, Polyps Cystic fibrosis
Beware chronic wet cough or sputum production; esp. if with typical CF bugs
Beware asthma plus … rectal prolapse, poor weight gain, polyps
Do not let age put you off the diagnosis
If in doubt – do a sweat test Mimics of Asthma: esophageal disease Contamination from below Gastroesophageal reflux
Contamination from above Incoordinate swallow, laryngeal cleft
Contamination from the side H-type fistula (congenital and acquired)
Aspiration
Evidence of significant acid reflux • Barium swallow study • pH monitoring • Radioisotope gastroesophageal scintigraphy. • Esophagoscopy and/or biopsy
Evidence of aspiration? • Milk scan. • lipid-laden macrophages BAL Swallow study Anterior
H-type fistula – note gastric contents (arrow) Mimics of Asthma: congenital lung disease Intraluminal – webs
Intramural – complete rings; airway malacia
Exrtaluminal – vascular rings/slings, congenital thoracic malformation What caused the Problem?
History • A 4 month-old with prominent noisy breathing when agitated and during respiratory infection
Physical examination • Staccato cough • Occasional apnea and bradycardia • Subcostal retraction Pulmonary artery sling
A rare vascular anomaly in which the left pulmonary artery arises from the right pulmonary artery.
Compression caused by the sling can produce obstructive emphysema, atelectasis of the right and left lungs, or both.
Most infants are affected within the first few weeks of life and present with stridor, respiratory distress, cyanosis, wheezing, and/or pneumonia.
Treatment: surgical relocation of the left pulmonary artery from its right-sided origin to the main pulmonary artery, anterior to the trachea A 3-month-old with noisy breathing…. Tracheomalacia
Structural abnormality of the trachea characterized by collapse of trachea’s cartilaginous walls
Can occur with other congenital anomalies such as laryngomalacia, tracheoesophageal fistula.
Prognosis is good in children with no associated problems. Most affected infants improve spontaneously by 6 to 12 months of age.
Treatment options: positive pressure ventilatory support, tracheal surgery, placement of a tracheal stent, or suspension of the trachea (tracheopexy).
Atypical features from history……
Symptoms dating from birth or shortly afterwards
Wheeze which is continuous throughout the 24 hours
Wheeze which doesn’t have definite attacks lasting a few days separated by clear symptom free (or largely symptom-free) intervals of weeks or months
Failure to thrive
Total failure to respond to anti-asthmatic medications is suggestive, but many young children with typical causes of wheeze also fail to respond
Atypical features from physical examination….
Asymmetry of chest or bony anomalies
Unilateral or localized wheezing or reduced air entry
Monophonic wheeze, especially if purely inspiratory
Crackles, marked tachypnea and central cyanosis other than during severe exacerbation
Clubbing of the nails
Marked upper respiratory tract or ear disease
Neurological impairment Management of a wheezy infant and preschool child
No evidence–based guidelines, and not even consensus statements, on the right approach to management of typical wheeze Diagnostic algorithm for wheezing in preschool children How to do it: Trial of Therapy
SYMPTOMS
THERAPY THERAPY Treating the wheezy infant/preschool child who does not respond to medication
No general consensus
Make sure the child is receiving the medicine regularly and correctly. Trial of therapy: oral CS + bronchodilator
Rule out other diagnosis
If other diagnosis are ruled out, wheezing is viral related and not responding to steroid Explain to the parents the nature of the problem, that anti-asthmatic medication is not indicated and that the situation is likely to improve with time. Wheezing following RSV bronchiolitis is very likely to become less severe over the next few months
If once non-responsive to steroid ≠ always non-responsive: potential asthmatic who is not responsive at the beginning most likely to begin to respond to corticosteroids over the next few months What to tell the parents of the typical wheezy infant or preschool child
Does the wheezy infant/preschool child really have asthma?
Will the child grow out of the wheezing illness?
Does the child need long-term treatment?
Does the wheezy infant/preschool child really have asthma?
Personal or family history of asthma or allergies including infantile eczema Discrete attacks with complete symptom-free intervals Symptom worse at night Apparent good response to bronchodilators or corticosteroid if used Normal plain chest radiograph or just hyperinflation Eosinophilia and elevated total IgE Positive bronchial provocation challenge Will the child grow out of the wheezing illness? Clinical predictive index for future asthma
Frequent wheeze during first 3 years plus: 1 major criterion: •Parental asthma •Patient eczema 2 of 3 minor criteria:
•Eosinophilia 95% of children •Wheeze without colds with negative index had no •Allergic rhinitis asthma between age 6-13 years
Phenotype assigned to guide prognosis & management
Castro-Rodriguez AJRCCM 2000 When a wheeze/respiratory noise is not an asthma: clues for alternate diagnosis Points in the History – 1
Is it really wheeze?
Upper airway symptoms prominent?
Symptoms from first day of life
Sudden onset symptoms
Chronic moist cough/sputum When a wheeze/respiratory noise is not an asthma: clues for alternate diagnosis
Points in the History - 2
Worse after meals, irritable feeder, arches back, vomits
Systemic illness or immunodeficiency
Continuous, unremitting symptoms
What happens during sleep? When a wheeze/respiratory noise is not an asthma: clues for alternate diagnosis
Points in the Physical Examination -1
Clubbing, weight loss, failure to thrive
Upper airway disease – tonsils, rhinitis
Unusually severe chest deformity
When a wheeze/respiratory noise is not an asthma: clues for alternate diagnosis
Points in the Physical Examination -2
Fixed monophonic wheeze
Stridor (monophasic or biphasic)
Assymetrical signs
Signs of cardiac or systemic disease